SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb0b9a59642b11772d330820da510061fc89269eee1479928d2a5a167f151317' 
  AND token = 'Xk9a/vd2xRGJ9KwhDyf9hu8C2VvFFyP1hPtrqMRWDFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}